Dr. Xinjian Zhou

Researchers at Sandia National Laboratories have created the first
carbon nanotube device that can detect the entire visible spectrum of
light, a feat that could soon allow scientists to probe single molecule
transformations, study how those molecules respond to light, observe how
the molecules change shapes, and understand other fundamental
interactions between molecules and nanotubes.

“In our eyes the neuron is in front of the retinal molecule, so the
light has to transmit through the neuron to hit the molecule,” says
Sandia researcher Xinjian Zhou. “We placed the nanotube transistor
behind the molecule  a more efficient design.

Zhou and his Sandia colleagues François Léonard, Andy
Vance,
Karen
Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently
published a paper, “Color Detection Using Chromophore-Nanotube Hybrid
Devices,” in the journal Nano Letters.

The idea of carbon nanotubes being light sensitive has been around for a
long time, but earlier efforts using an individual nanotube were only
able to detect light in narrow wavelength ranges at laser intensities.
The Sandia team found that their nanodetector was orders of magnitude
more sensitive, down to about 40 W/m2  about 3 percent of the
density of
sunshine reaching the ground. “Because the dye is so close to the
nanotube, a little change turns into a big signal on the device,” says
Zhou.

Xinjian Zhou, Ph.D. is Postdoctoral Fellow at Sandia National
Laboratories where he specializes in research and fundraising in the
fields of Nanoscience and Nanotechnology, Physics, and Material Science.